1. Field of the Invention
The present invention relates to a golf club head and method manufacturing the same, more particularly to a club face with a high-strength part which can improve its durability, directionality for hit ball and rebound performance.
2. Description of the Prior Art
In general, in order to increase a distance of a hit ball, a golf club head with a great volume is proposed. Such a golf club head, for example, comprises a titanium alloy such as Ti-15-Mo-5Zr-3Al or Ti-6Al-4V.
By the way, in order to use a golf club in an official competition, a club head must have a coefficient of restitution less than 0.830. Most of club heads already sold have a coefficient of restitution exceeding 0.830. Therefore, club head makers have to make a club head with coefficient of restitution smaller than before.
In general, the coefficient of restitution of a club head becomes large by making rigidity of a face portion thereof small. For example, if a thickness of a face portion of a club head is made small, the coefficient of restitution of the club head will become large. Therefore, in order to reduce a coefficient of restitution of a club head, it is necessary to enlarge a thickness of a face portion.
However, if the thickness of the face portion is enlarged, a weight of the face portion will increase relatively and a depth of center of gravity of a club head will become small.
For example, in a hollow driver club head made of titanium alloy with a head volume of 400 cm3 and an area of club face of 40 cm2, if a thickness of the face portion of the club head increase by 0.5 mm, a weight of the face portion will increase 5 g or more in general.
Such a club head with a small depth of the center of gravity does not have the good directionality of a hit ball since the rotation of the club head becomes large at the time of a misshot.